In many situations, modem call failures on AS5200 and AS5300 Series
Access Servers can be traced to problems with the Modem ISDN channel
aggregation (MICA) hardware. This document helps you identify and troubleshoot
common problems associated with the MICA hardware. It also shows how to
identify a specific faulty modem component for replacement, rather than
replacing all the modem hardware.

The MICA carrier card includes ten slots in which you can install six-
or 12-port modem modules. Hence, in a fully populated carrier card you can have
either 60 modems (if using the six-port modules) or 120 modems (if using the
12-port modules).

Note: Since there are two carrier card slots, a fully populated chassis can
have 120 (if using the six-port modules) or 240 (if using the 12-port modules)
modems per chassis.

This carrier card fits into one of the two slots on the chassis as
shown in the diagram below:

Individual modem modules are plugged into single in-line memory module
(SIMM) slots on the carrier card. Refer to the document
MICA
Modem Cards for information on identifying a specific module on the
carrier card. A failure of one or more of the modules will not affect the
operation of the rest of modem modules on the carrier card.

The following table describes the LEDs on the MICA carrier card:

LED

State

Description

Activity (ACT)

Flickering

There is transmit activity on one or more modems on this
module.

Off

There is no modem call activity on the MICA module
cards.

Board OK (OK)

One flash

The carrier card is powering up.

On

The card has passed the initial power-on diagnostic tests and
is operating normally. This state is entered after the firmware is downloaded
to the modems.

Off

A fault condition is present on the card.

These LEDs are used in the troubleshooting procedure later in this
section.

Note: There are 2 types of MICA Carrier Cards: CC and CC2. CCs accept only
HMMs (6-port modem modules) while CC2s can accept both HMMs and DMMs (12-port
modem modules). You must not insert DMMs in a CC. Refer to the section
Troubleshooting Procedure for information on identifying the type of Carrier
Card that is installed in the chassis.

As discussed previously, each carrier card can contain up to ten MICA
modem modules. Each modem module can be either a six-port or 12-port module.
The six-port modem module is also referred to as Hex Modem Module (HMM) while
the 12-port module is referred to as Double Density Modem Module(DMMs). A
diagram of a DMM partially inserted into the carrier card SIMM slot is shown
below:

MICA modems are implemented with one digital signal processor (DSP) for
each two ports, and one control processor (CP) per six ports. The set of six
MICA modems controlled by one CP is known as a "hex"; a HMM consists of one hex
and a DMM contains two hexes (hence the name "Double" Density). From time to
time, a DSP or a CP can fail. This causes all subsequent modem calls into that
DSP or CP to fail to trainup.

Since DSPs or CPs on a modem module cannot be separated from the other
modems on the module, a DSP or CP hardware failure may require the replacement
of the entire HMM or DMM.

Once the boot process is complete, the router downloads the
firmware to the individual modems.

Once the Access Server completes booting up, verify that the OK LED
on the carrier card is ON (solid).

Perform a show running-config. Towards
the end of the output you should see all the async lines.

For example, if you have two carrier cards with 48 modems per slot
then you should see 96 lines (2 x 48)

line 1 96

Note whether the line number range matches the number of modems
installed on the carrier card. For example, in the above case, if you notice
that the router recognizes only line 1 90 , then we can conclude that six
modems are not recognized.

Perform a show version command.

Verify that the output includes the line 96 terminal
line(s). The number of terminal lines should match the number
of modems installed on the chassis.

Perform a show modem and
show modem version command.

The show modem output should display
every individual port (for a total of 96). In the show modem
version output , verify that the modem firmware version is as
expected. You should also check to see that every modem module has either six
(for HMM) or 12 (for DMM) modems.

Once you have gathered the information as specified above, proceed to
one of the hardware symptoms below.

When dealing with unrecognized modem issues, we must first determine
whether:

None of the Modems (on the entire chassis) are recognized. This means
that the Access Server does not recognize the presence of the MICA carrier
card.

None of the Modems (on a single MICA carrier card) are recognized.
The Access Server recognizes the presence of the carrier card, but none of the
modems within the carrier card are recognized.

All Modems (on a DMM or HMM within the carrier card) are not being
recognized. The Access Server recognizes only some modems on the carrier card.
The unrecognized modems will all be in one particular DMM or HMM modem module.

If the previous steps do not show any lines available on the chassis,
then proceed with the instructions below:

Power down the router.

Remove and reseat the MICA carrier card. Tighten the two captive
screws.

Power up the router. If both carrier cards are not recognized (OK
LED is off), then the problem could be caused by the chassis, carrier card or
collectively all the modem modules. Try inserting the carrier card in another
chassis.

Verify that both carrier cards are correctly identified. If either card
is not identified then proceed below:

Power down the router.

Remove the two carrier cards and swap them between slots on the
chassis. Hence, the carrier card in slot 1 is now in slot 2 and vice versa.
Power up the router.

For more information on removing and inserting the cards refer to
the document
MICA
Modem Cards.

If the symptom continues, then the problem could be due to the
carrier card or all the modem modules in it. If the problem remains with the
particular slot, then the issue is a chassis or slot failure. Replace the
chassis.

If the steps above show only a few missing lines, then we can conclude
that the HMM or DMM for those modems is not functioning:

Swap the particular HMM or DMM within the same carrier card. If the
problem follows the HMM or DMM, then replace the HMM or DMM. However, if the
problem does not follow the module, rather it remains with the the slot, we can
conclude that the particular slot on the carrier card is faulty. Replace the
carrier card.

Tip: The show modem version command specifies the modem module each modem
port belongs to. Hence, if a certain range of modems are not being recognized,
you can use the show modem version command to determine the particular modem
module that is affected and swap out that module. In the sample shown below, we
can conclude that modem module number 5 is not recognized, hence we reseat or
replace that module.

Note: If the MICA Carrier Card is type CC, then ensure that only HMMs are
installed on that Carrier Card. DMMs cannot be installed on CC Carrier Cards.
However, this restriction is not applicable to CC2s. To identify whether the
Carrier Card is type CC or CC2, use the show modem
version command. If the output indicates that the Board ID is
0x47, then the Carrier Card is CC. If the Board ID is
0x4C, then it is a CC2. Here are some examples:

Reflash the modem portware. This involves manually reloading the
modem firmware to the modem just as if you were upgrading firmware.

For Cisco IOS Software Releases 12.0(5) and earlier, use the
copy flash modem command. This transfers the modem
firmware in flash to the modems. Refer to the
Command
Reference for more information on the copy
modem command.

For Cisco IOS Software Releases 12.0(5) and later, use the
spe and firmware location
commands. For example:

In very rare circumstances, modem errors constantly scroll on the
console, causing the router to reboot.

This usually happens when a HMM or DMM is bad. Note that the messages
scroll very quickly, making it difficult to determine the bad modem module
generating the error message. To determine the offending modem module perform
the following steps:

Remove all the modem modules (HMMs or DMMs) from the carrier card,
insert the carrier card back into the chassis and power on. Check whether the
errors still appear. Power off the router.

Add a single Modem Module to the carrier card and power on. Check
whether the errors still appear. Repeat this step until the messages reappear.
We can now conclude that the last inserted MM is generating the errors. Replace
that particular modem module.